All about electrically insulating plastics: insulation and applications
Electrically insulating plastics are indispensable materials in electrical engineering and industry. They offer a combination of high dielectric strength, mechanical stability and thermal resistance, making electrical systems safe and efficient. This article examines the properties, applications and selection criteria for electrically insulating plastics.
What are electrically insulating plastics?
Electrically insulating plastics are non-conductors that prevent the flow of electric current and thereby act as insulators. They offer a high dielectric strength and low electrical conductivity.
GOBA processes insulating plastics as polyester films and insulation materials for the electrical industry.
How are electrically insulating plastics manufactured?
Manufacturing takes place via specialized polymerization techniques. Additives such as ceramics or glass fibres reinforce mechanical properties and environmental resistance.
Examples of electrically insulating plastics
- Polyimide (PI): Heat-resistant and mechanically stable
- Polycarbonate (PC): Impact-resistant and electrically insulating
- Polyethylene terephthalate (PET): Good electrical and thermal properties
How does electrical insulation work?
Electrical insulation in electrical engineering
Electrical insulation describes the ability of a material to prevent the flow of electric current by acting as an insulating barrier. Insulators such as plastics prevent live parts from causing unwanted energy transfers.
Measuring electrical conductivity
The electrical conductivity of a material is measured in Siemens per metre (S/m). Electrically insulating plastics have an extremely low conductivity, often in the range of 10⁻¹⁵ S/m, which makes them ideal for high-voltage applications.
What applications do electrically insulating plastics have?
Electrical engineering
- Printed circuit boards: As insulators between different layers
- Cable insulation: Prevents current losses and protects against short circuits
- Transformers: Insulation materials with high surface leakage current resistance
Industry
- Motors: Insulated components for stators and rotors
- Generators: Protection against electrical flashovers
Medical technology
- Safety insulation: Prevents electrical transfer in sensitive devices
Examples
- High-voltage insulation: Protection against voltage flashovers in power lines
- Device enclosures: Electrically insulating enclosures for safety purposes
What are the advantages of electrically insulating plastics?
- High dielectric strength: Prevents flashovers and ensures safe operation
- Low electrical conductivity: Extremely low and therefore negligible conductivity provides safety in high-voltage applications
- High surface leakage current resistance: Prevents the occurrence of leakage currents
- Resistance to thermal and mechanical loads
- Durability: Resistance to contamination, environmental influences and high temperatures
How do you select the right electrically insulating plastic?
Key factors
- Electrical properties: High dielectric strength and low conductivity are essential
- Mechanical strength: Consider mechanical strength and resistance to environmental influences depending on the area of application
- Temperature resistance: The plastic must be suitable for the relevant temperature range
- Area of application: Insulating materials are adapted for specific applications, e.g. cable insulation or enclosures
Material comparison
- Polyimide: Excellent for high temperatures
- Polycarbonate: Mechanically robust, less heat-resistant
- PTFE: Resistant to chemicals and temperatures
GOBA Takeaway
Electrically insulating plastics are indispensable for safe and efficient electrical systems. They combine dielectric strength, thermal stability and mechanical resistance. The right material choice depends on the specific requirements of the application.